It’s a simple concept, every day you fire it up and enter your weight, it keeps track. Yay. However, what it also does is allow you to chart your weight over time, and builds an exponentially smoothed average to help you watch your over-all weight trends, without letting an ice cream day hurt you.
It also allows you to set and measure goals, and based on your current and target weight will give you an estimate as to how you need to adjust your intake.
At $9.95 it’s not the cheapest app on the AppStore, but skip a couple fast food lunches and you’ll have covered the $9.95.